Gas is selling for as low as $1.53 in Detroit; but one analyst predicts it won't last.

Michigan has the lowest average gas price in the country. But for how long?

Advice from one analyst: Fill up, now!

Two groups that track gas prices -- GasBuddy.com and the American Automobile Association -- both put Michigan at the top of their low-price gas lists, which they compiled daily. Gas is selling today at $1.79 a gallon and $1.80, respectively.

Michigan edged out Oklahoma, which has an average just a few tenths of a cent more, and Ohio, at $1.82 a gallon.

Nationwide, the average price is $2.03.

But, GasBuddy's senior petroleum analyst Patrick DeHaan urged drivers seeking to save a few dollars to fuel up right away. By Tuesday morning, he predicted, gas stations will have raised prices significantly, and Michigan probably won't be No. 1 in the country anymore.

"It's a matter of time," he said. "We are certainly not Oklahoma, nor are we in the South where much of the crude oil infrastructure exists. So this is something that maybe happens every one or two years and the stars align and you see Michigan leading the nation."

Prices had been forecast to fall in Michigan earlier this month, dropping 48 cents from a month ago, to lows now that have not been seen since 2009.

In fact, DeHaan said, he found average prices in 2001 that are higher than they are now.

In metro Detroit, the average gas price is $1.79 a gallon, which some of the cheapest prices of $1.53 at BP stations on Michigan Avenue in Dearborn and Joy and Greenfield in Detroit.

Among U.S. cities tracked by GasBuddy, Kalamazoo, Flint, Grand Rapids and Toledo have some of the lowest average city prices in the country at $1.67, $1.70, $1.74 and $1.76 a gallon, respectively.

Reasons for the cheap gas include: Crude oil prices have been low compared to previous years as inventories build. Russia and Saudi Arabia continue to produce oil, while China's economic growth has been slower than projected, and domestic inventories are nearing record levels.

In addition, Midwest refinery production has recovered, improving prices; and financial markets have been resilient despite terrorist attacks in Paris.

DeHaan predicted that prices will come up in Michigan; but, will likely be around $2 until mid-February.

"I think prices should spend more time under $2 than over $2 through Valentine's Day," he said. "Once the sweetness of that milk chocolate and all those roses dies down, then we'll be talking about higher gas prices -- and that's just going to be the seasonal change."

States with the cheapest gas

Here are the five states with the least expensive average regular gas prices per gallon, according to GasBuddy.com: